LESSON 1

Potential Uses of Optical Illusions

Rapid Reading
Look at the illustration below. What do you see? Some people might see arabbit facing to the right, while others might see a duck facing to the left.
This illustration shows how our eyes can be tricked, what is called an opticalillusion. Such illusions have been used in various ways which we can see in5
our daily lives.
First, one example is the manner in which they have historically been
incorporated into structural designs. The karesansui (dry landscape) gardenat the Zen temple Ryōanji in Kyoto illustrates such a use. Its surface may
look completely level, but actually, it inclines towards the garden’s southeast corner. Also, the west-side earthen wall is slightly higher at its 10
northern end. These factors create an optical illusion that makes thissurface look deeper. This effect is the same as the one seen in the Ponzo
Illusion (Figure 1), in which the horizontal line closer to the top looks longer
than the line below it, even though the two are exactly the same length.
Second, another optical illusion can be seen in the picture below, which 15
shows the interior of a house that appears to have an extremely high ceiling.
The effect is caused by the Fick Illusion (Figure 2), in which the vertical line
seems longer than the horizontal line despite their lengths being precisely thesame. Using this effect can make a room look more spacious than it actually
20is.
Third, another technique employed recently is to create, on a twodimensional surface, the appearance of a three-dimensional object. In one
train station, for instance, people are frequently unable to find an elevator
located in a blind spot. To assist them, a sign that appears to be threedimensional is painted on the floor. The sign is of significant help in sending 25
people in the right direction.
Last, they can be used at an intersection with no traffic lights. Crosswalk
designs that look three-dimensional have been painted on some roads toprevent traffic accidents. From the viewpoint of approaching drivers, it looks
like large concrete blocks are in the road. Hopefully, drivers will slow down 30
when they see them, before nearing the crosswalk.

5Of course, the power of optical illusions is limited. It cannot make agarden larger, nor can it make a ceiling higher. Over time, a crosswalk
painted to appear three-dimensional will lose its effectiveness in preventing
accidents. Drivers will come to realize that what they are seeing is just anillusion. Nonetheless, with such limitations kept in mind, it should bepossible to find an even wider variety of useful applications of opticalillusions.
total words 435
min.

TRUE OR FALSE

1. ()

2. ()

3. ()

4. ()

5. (sec.

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1. The karesansui garden uses the same type of optical illusion as the Ponzo Illusion.
2. In the Fick Illusion, the upper line looks longer than the lower line, even though they are the same length.
3. Drivers believe without a doubt that three-dimensional crosswalks on streets are real concrete blocks.
4. Optical illusions can make gardens larger and also ceilings higher.
5. In spite of their limitations, optical illusions have the potential to be effectively used in wider ways.

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